New here, first post, thank you everyone in advance for helping me to figure out what is going on with my truck. I've been online researching for days now and cannot seem to find a solution. Here it goes;

2003 Dodge Ram 1500 4.7 with 230,*** miles.

Truck began to rough idle (up/down, close to stalling, kinda like what old lawn mowers do sometimes) a couple weeks ago. Only when first starting in the morning, fine the rest of the day. Would go away once warm.

A couple weeks later, it began really rough idling for 3-4 seconds then stalling. This would only happen occasionally, and only when the truck was hot. I.e. Drove 20 miles, turned it off, waited 30-60 minutes, try to start and truck would rough idle 3-4 seconds and stall. It would start fine the next morning.

Last week, truck will not start, cranks over but no go.

Check engine light had been on, it was throwing a P0440 code. I recently got a new aftermarket fuel cap (left the other one on the side of the road somewhere). I figured it's the cap, checked all the hoses around the canisters etc, everything seems fine. I'm also under the assumption that an EVAP code would not prevent the truck from starting so this is probably a separate issue.


This is what I've done;

Checked for spark. Good.
Checked for fuel. Good.
-Did this by opening the little bleed valve on fuel rail, gas comes shooting out. I can also hear the fuel pump turning on. It has 3/4 tank.
Checked fuses. Good.
Checked Relays. Good.
-Bought new relays and swapped out the ASD and FUEL PUMP anyway.
Replaced camshaft position sensor.
Replaced crankshaft position sensor.
Cleaned throttle body.
Replaced throttle position sensor.
Cleaned out as best I could the IAC.
Sprayed starter fluid into the intake and it sputtered a little.
Unplugged cam sensor, cranks, throws a cam sensor code.
Unplugged crank sensor, cranks, doesn't throw any code.
Jumped ASD relay, cranks, throws ASD codes.

I'm kinda stuck on where to go next. I figured since I'm getting codes when unplugging stuff that the PCM is fine. Fuel? More sensors?

Any help, suggestions, thoughts would be greatly appreciated.

Thanks!

 

What brand sensors?

If you were getting spark, crank sensor is likely good. Might see if you can beg/borrow/rent a noid light from your local parts store (unless you have one?) and see if you are getting injector pulse.

 

Sensors are Duralast.

I can probably just make a little noid light right? Little bulb and some wires seems like it might do the trick.

 

Even test light would likely work.

Put the mopar sensors back in and test. These trucks really dislike aftermarket sensors........

 

I also swapped the old cam/crank sensors back in one at a time to check if I had gotten faulty parts.

 

Leave the mopar sensors in, and test for injector pulse.

Also, there *might* be a specific procedure for installing the cam sensor........ not sure on that though.

 

No pulse.

 

Also, with the ignition in the "On" position, I'm only getting .584 volts exactly out of each injector connection.

EDIT: Just found this in the manual.. probably explains my .5 volts.

"Battery voltage (12 volts +) is supplied to the injectors through the ASD relay. The ASD relay will shutdown the 12 volt power source to the fuel injectors if the PCM senses the ignition is on, but the engine is not running. This occurs after the engine has not been running for approximately 1.8 seconds."

 

Don't check injectors with a voltmeter. Compare their resistance to spec. 14 Ohms I believe is about generic spec. You're seeing the voltage drop anyway, which might not be much help, due to control ckt duty cycle being variable while running. The same source for injectors and coils are from ASD relay. Check for battery voltage NOT RUNNING. The other wire is the control wire. It should pulse ground, with a test light.

Put a fuel pressure gauge on it and route it where you can see it while it runs bad. Take a fuel sample while you're in there.

Be aware that you have pretty much gone beyond the mechanical limits of a 4.7 now. It's possible you have some valve spring issues as well.

 

Okay! Got it to start, but now it has new problems that weren't there before.

To start it I had to really pump the pedal. Then she idles at around 1400rpm.

Drove it around the block and it will not shift out of first.

Getting a p0522 code. I haven't reset the codes since I got it to run and that could just be from cranking it over so much without running.